Lightning conductors are made of
iron
chromium
copper
steel
Correct Answer :
C. copper
Related Questions
At what temperature do the Fahrenheit and Kelvin scales give the same reading?
212°
32°
-40°
0°
When two similar sources vibrate with slightly different frequencies, a regular rise and fall occurs in the loudness of tone. This phenomenon Is known as
doppler effect
beats
resonance
echo
A wire conveying a current deflects a pivoted magnetic needle. This was discovered by
Marconi
Oersted
Faraday
Ohm
A bucket of water is hung from a spring balance. A piece of iron is suspended in the water without touching the sides or touching the bottom of the bucket. The reading of the spring balance
will increase
will decrease
does not change
varies with the increase of depth of the immersion of the iron piece
If a body weight 12N on the surface of the earth, how much will it weigh on the surface of the moon where acceleration due to gravity is only one-sixth of that on earth's surface?
12N
2N
10N
6N
The period of oscillation of a simple pendulum depends upon
the mass of its bob
the material of the bob
the amplitude of vibration
acceleration due to the gravity at the site of experiment
When a bullet is fired from a gun
the gun moves forward
the gun jumps up
the gun does not move
the gun recoils with the same momentum as the bullet
Warm air will hold more water vapour than cold air because
it is lighter
it has more water vapour in it
its molecules are close together
its molecules are far apart
Which of the following wires of same dimensions offers least resistance to the ,flow of current?
copper
aluminium
silver
nichrome
A lactometer is used to
find out the specific gravity of liquids
measure the volumes of liquids
test the purity of milk
determine the strength of acid in car batteries
In which of the following will a piece of iron weigh most?
in air
in an atmosphere of oxygen
in an atmosphere of CO2
in vacuum
When are temperature resistance
increases
decreases
remains the same
first increases then decreases
The strength of an electromagnet can be increased by
increasing the length of the coiled wire
increasing current supply
increasing the size of the iron core
All the above
Which of the following is wrongly matched?
electric current - ampere
resistance - Ohm
electric power - volt
electric charge Coulomb
Formation of shadows can be explained by
rectilinear propagation of light
reflection
refraction
total internal reflection
Stars twinkle because of
refraction of light from them through air
reflection
absorption
All the above
The electron has a mass equal to
1.9 x 10-13 kg
9.1 x 10-31 kg
1 x 10-15 kg
1.6 x 10-19 kg
The base of an electric iron is brightly polished mainly
to make it smooth and frictionless
to make it rust - proof
to reduce heat loss by radiation
to make it more durable
The Indian Space Research Organisation (ISRO) is located at
Thumba
Bangalore
Ahmedabad
New Delhi
The number of electrons in the outer orbits of a nucleus gives
the mass number
atomic number
atomic weight
absolute number
Echoes are produced by
the reflection of sound waves
the refraction of sound waves
the interference of sound waves
reverberation of sound waves
The ballistic missile, Agni 11, tested by India has a maximum range of
1000 km
1500 km
2000 km
500 km
Acoustics' la a branch or study dealing with
historical sites
architecture
sound
trigonometry
A pressure gauge for fluids is called
a hydrometer
a manometer
a lactometer
an anemometer
Of the following types of electromagnetic radiation which has the longest wavelength?
ultraviolet rays
gamma rays
radio waves
infrared waves
A man Jumping out of a moving train is thrown
forward
backward
sideways
None of the above
When the velocity of a body is halved
its momentum is halved
its kinetic energy is halved
its acceleration is halved
its potential energy is halved
The unit of heat energy is
watt
degree
joule
erg
Alternating Current (AC) is more advantageous than direct current because
it can be transmitted easily and efficiently
Alternating Current (AC) loses the least amount of energy when transmitted at high voltages
Alternating Current (AC) voltage can be easily increased or decreased
all the above
When a swing is drawn to a side Its potential energy In relation to the earth
increases
decreases
remains the same
is constant